Can batteries replace coal plants?

In 1997, when Dan Foley was managing Commonwealth Edison's electrical grid, mornings meant firing up two coal-fired generating plants to keep pace with the sudden spike in electricity as nearly 3 million Chicagoans switched on their lights, hair dryers and televisions.

"Mornings used to scare the hell out of us," he said.

Seventeen years later, Foley thinks he has the answer to scary mornings: batteries.

Foley, founder of Chicago-based energy development firm Glidepath, has been quietly developing three $20 million battery storage facilities in northern Illinois that can be tapped to quickly deal with fluctuations in demand on the grid. In other words, power grid operators wouldn't have to worry about cranking up plants for sudden spikes in load.

With a combined 60 megawatts of capacity, the facilities, which look like rows of shipping containers, together represent the largest project of its kind in North America. They are to be built in Joliet, McHenry and West Chicago.

Glidepath recently sold two of the facilities for an undisclosed price to a renewable energy company Foley declined to name. ComEd expects the three projects to hook into its electrical grid in the spring.

Such battery projects also offer other advantages: helping to regulate swings in power from wind and solar generators, depending on whether the sun in shining or the wind is blowing. The electrical grid can't absorb or regulate power bursts. Battery storage facilities can store that power for when it's needed.

"It's the equivalent of a shock absorber in a car," Foley told members of Joliet's Planning Commission about his battery project. "If there's bumps in the (electrical) system … what it does is it smooths out those bumps, it adds reliability and stability to the system."

Advocates of wind and solar power have long touted the potential that battery storage could hold for integrating renewable energy into the grid. In 2011 and 2012 the federal government invested money in such projects under the American Recovery and Reinvestment Act. But when funding dried up, so did development, according to Navigant Consulting.

Today, there are about 270 distributed energy storage projects across the United States with a combined capacity of 212 megawatts, according to Green Tech Media Research.

But now the industry is expected to surge, in part as a result of a ruling by the Federal Energy Regulatory Commission that increased the pay for "fast"-responding energy sources like batteries.

A report recently released by Navigant Research predicts that global energy storage is expected to grow dramatically over the next decade, from 538 megawatts this year to 20.8 gigawatts. A gigawatt can power about 1 million homes.

Each of Glidepath's sites is composed of nine containers, each with 80,000 lithium-based batteries, on a footprint of about 100 feet by 200 feet. They will be equipped with fire suppression, and a chilling unit in case of overheating.

A lot has changed since the days Foley helped operate the electrical grid. Among other things, the ComEd service area is part of a larger grid system.

But some things remain the same. Traditional power providers are still called upon to remain at the ready to account for the unpredictability of renewable energy, blocking the amount of traditional generation that can be displaced by those naturally available resources.

Without those power providers available to keep electrical current steady, ComEd's grid is susceptible to blackouts and brownouts, said Joe Svachula, ComEd's vice president of engineering and smart grid.

"The system is designed to protect itself," Svachula said. "If we don't have the generation matched to the load, the frequency starts to rapidly drop and equipment would be destroyed. The worst-case scenario of poor frequency is, the grid can break off into islands, which leads to blackouts. That frequency response is important. Until now, that's been from older generators, and there's a need to replace it."

Jason Blumberg, CEO of Energy Foundry, a Chicago-based venture fund paid into by Commonwealth Edison and Ameren Illinois shareholders, is a Glidepath investor. Glidepath, which operates out of the Energy Foundry's offices, is testing its technology on ComEd's grid.